High speed multiple cylinder hydraulic vibrator



Nov. 29, 1955 D, PEARSON ET AL HIGH SPEED MULTIPLE CYLINDER HYDRAULIC VIBRATOR Filed Sept. 23, 1950 5 Sheets-Sheet l /N VEN TO ES 'DAwo PEARSON,

AND JULIUSYAEMAK, BY W I I ATTY Nov. 29, 1955 D. PEARSON ET AL HIGH SPEED MULTIPLE CYLINDER HYDRAULIC VIBRATOR 3 SheetsSheet 2 Filed Sept. 25, 1950 W a l 8 5 5 4 5 y Rx? ||2 an, I; g 4\\\\N 4 =/J\UM\W UM l V 4 L m 6 4 f? 7 m A PAY/ iz 13 DJ Nov. 29, 1955 D. PEARSON ET AL 2,725,039

HIGH SPEED MULTIPLE CYLINDER HYDRAULIC VIBRATOR Filed Sept. 25, 1950 s Sheets-Sheet 3 I I '70 57 47 65 ll Ealq. '7

i /NVEN7'OES, I I3 48 64 58 DAVID PEARSON,

AND JULIUS YAEMAK) United States PatentOflice 2,725,039 Patented Nov. 29, 1955 HIGH SPEED MULTIPLE CYLINDER HYDRAULIC VIBRATOR David Pearson Julius Yarmak, Wakefield, England, assignors to The Jeffrey Manufacturing Company, a corporation of Ohio Application September 23, 1950, Serial No. 186,361

2 Claims. (Cl. 121-15) Mechanical vibrators are already well known in which vibration impulses are created by centrifugal forces of an eccentric rotor and springs or by two eccentric rotors adjusted parallel to each other and rotating in opposite directions, or by an unbalanced crank mechanism imparting a quick reciprocating motion to a relatively heavy body. Among other well known types of vibrators may be mentioned electro-magnetic vibrators in which the vibration impulses are produced by electro-magnetic forces acting alternately in two opposite directions, or in one direction against springs, and pneumatic vibrators in which a comparatively heavy body, which comprises in most constructions a piston moving inside its cylinder, receives a reciprocating motion of high frequency or alternatively, there may be used a blowing or percussive striking eflect.

A main object of the present invention is to provide an improved vibrator which is generally more adaptable and eflicient than those in use at the present time.

According to the present invention there is provided a vibrator for imposing alterable force impulses of concontrolled by valve means which are also incorporated in said block and which are in turn controlled by the reciprocating striker or strikers.

Use of fluid, mainly hydraulic oil of low viscosity, under high pressure permits the use of relatively small diameter rams in the vibrator unit and a piping arrangement that is more compact than is possible with pneumatic vibrators. A much higher efficiency is thus attained with hydraulic transmission, as compared with pneumatic transmission. A hydraulic vibrator constructed in accordance with the invention is, furthermore, more flexible in its connection with its driving motor and is capable of imposing vibration impulses of high frequency (2,000 to 4,000 per minute) and of much greater magnitude than can be obtained with the present known types.

In order that the invention may be clearly understood and readily carried into effect one embodiment thereof will now be more fully described with reference to the accompanying drawings wherein:

Fig. l is a sectional elevation taken partially on the irregular line II of Fig. 3 and showing one form of vibrator according to the invention fitted to a machine working structure, the latter being partially broken away,

Fig. 2 is a sectional view taken on the line IIII of Fig. 1,

Fig. 3 is a sectional view taken on the line III-III of I Fig. l, the machine working structure being omitted,

siderable magnitude and high frequency on a machine working structure so as to cause vibration of said structure, the said vibrator including multiple movable bodies or strikers arranged to carry out quick reciprocating motion and to strike in two opposite directions on said machine structure under the influence of rams which latter are arranged for actuation by a motor-driven hydraulic pump through the intermediary of a practically incompressible hydraulic fluid. The machine structure against which the movable bodiesare arranged to strike is preferably provided with rubber or elastic cushions to control the blows to any desired degree and also to reduce noise. To achieve the reciprocating movement of each striker there may be employed one double-acting or two single-acting hydraulic rams to which fluid is admitted under pressure through suitable piping and valve gear, the strikers being arranged automatically to control the supply of the said fluid.

According to a more limited aspect of the invention, there is provided a vibrator for imposing alterable force impulses on a machine working structure, said vibrator including a combined valve and cylinder block, one or more elongated strikers slidably mounted on said block so as to be capable of reciprocation relatively thereto, each said striker having a striking body at each end, and further including hydraulic ram means incorporated in the said block for imparting reciprocating motion to each striker, said ram means being operable under the influence of hydraulic fluid fed thereto under pressure, and subsequently discharged therefrom, through bores and recesses in the block and said fluid supply and discharge being Fig. 4 is a diagrammatic developed section to a reduced scale of the vibrator according to Fig. 1 illustrating the various hydraulic connections and showing the bottom striker in a position in which its stroke to the left has been completed and the top striker in a position in which it is commencing its stroke to the left,

Fig. 5 is a view similar to Fig. 4 but showing the strikers in the next subsequent position in which the top striker has completed its stroke to the left and the bottom striker is commencing its stroke to the right,

Fig. 6 is a similar view to Figs. 4 and 5 but showing the strikers in the next following position in which the bottom striker has completed its stroke to the right and the top striker is commencing its stroke to the right, and

Fig. 7 is again a similar view to that shown in Figs.

4, 5 and 6 but showing the strikers in the next subsequent and final position in which the top striker has completed its stroke to the right and the bottom striker is commencing its stroke to the left, i. e. returning to the position in which it is shown in Fig. 4.

' It should be understood that the reference to bottom and top strikers and also to the movements of the strikers to the left and right is intended merely to identify the strikers and their respective directions of motion as viewed in Figs. 4 to 7 of the drawings.

Referring now to the drawings, the vibrator includes a valve and cylinder block 1 having two longitudinal through bores or holes 2 and 3 in which are slidably mounted two identical valve spindles 4 and 5 of the piston type. In the same block 1 there are provided four holes 6, 7, 8 and 9 comprising four cylinders in which four plunger pistons or rams 10, 11, 12 and 13 are arranged to operate.

On the block 1 are slidably mounted, by means of guiding flats 14 and 15 fixed to the block 1 by screws 16 (Figs. 1 and 3), two strikers 17 and 18 each having a striking body or head at each end and each having a longitudinal slot 19 (Fig. 2) for engaging guiding parts 20 and 21 of block 1 (Fig. 3). Strikers 17 and 18 are respectively provided at the inner end of each striking body with brackets 22, 23, 24 and 25 integral with the bodies of the strikers and these brackets abut the ends .of the valve spindles 4 and 5 respectively so that movement of the strikers is transmitted to the valves. The plunger pistons 10 and 11 thrust their heads 26 and 27 against the respective inner ends of the striking bodies of the striker 18, whilst the plunger "pistons '12-and 1'3thrust respectively upon the striking bodies of the striker 1'7 by their heads 23 and 29 as shown in Fig. l of the drawings. The plunger pistons or rains 10, 11, 12'and13 are kept in contact with the inner'ends of the striker bodies by pins 30 (Figs. 1 and 2).

On the front of the block 1 there is provided an inlet pipe 31 and a bifurcated discharge pipe 32 (Figs. 2 and'3).

The above structure as a whole may be fixed securely, by means of screws 33 and pins 34, to a base plate'35 which may form part of a machine working structure. The plate 35 in the example illustrated is-provided with two striker blocks formed by integral ribs or brackets "37 and 38 each of which, on the inwardly facing surface, is covered by a pad 39 or'40 of rubber or similar elastic material which is kept in position by steel or other metal plates 39a or 40a and by screws 41. These pads provide two elastic cushions to dampen and control theshock of impact and reduce noise of the blows transmitted by the strikers.

In operation, working hydraulic oil under pressure is supplied to the vibrator continuously from a pump (not shown) through the flexible pipe 42 connected to the inlet pipe 31 by means of an end fitting-43.

In the drawings the oil bores or recesses within the block 1 which containoil under high pressure are shown blank whilst those bores or recesses containing worked'or discharge oil are filled in with horizontal dashes. The general direction of oil flow is indicated by arrows in Figs. 1 to 3 of the drawings.

From the inlet pipe 31 the oil comes in through the central bore 44 (see Figs. 2 to 7 inclusive) and flows into both recesses 45 and 46 simultaneously. Depending upon the position of the valve spindles 4 and 5, the oil then flows to the working pistons 10, 11, 12 and 13. In the particular position of the valves shown in Figs. 1, 2 and 4, the oil under pressure is admitted through bores 47 and 48 to the piston 13 and simultaneously through bores 49 and 50 to the piston 10. In'this sequence the striker 17, which has already moved to one limited position, remains (under pressure of the piston 13) thrusting upon the bracket 38 whilst striker 18 moves in the direction shown by the arrow 51 (Fig. 4) under the influence of force imposed by oil pressure on piston. 10 until it imposes a-blow on members 4% and 40and thus on the bracket 38. At the same time piston 11 ispushed in by the opposite striking body of the moving striker 18 and oil is discharged through bores 52 and 53 into hole 55 of bifurcated pipe 32 and through the flexible hose 56, attached to pipe 32 bymeans of clip 56a, into an oil container (not shown in the drawings).

It will be understood'that movement of the striker 18 moves simultaneously the valve spindle'4 to the next subsequent position shown in Fig. 5. In this position the oil under pressure is still admitted to the piston 10 through opened bores 49 and 50 andthe piston continues to press striker 18 against the bracket 38. The oil under pressure is also admitted from bore 44 to piston 12 through bores 57 and 58. In this sequence piston 12 moves under oil pressure in the direction shownby arrow/ 59 and at the same time pushes striker 17 until it imposes a blow on bracket 37 via the members 39a and 39. Worked oil from piston 13 which is pushed'in, escapes through bores 48and 61 to bore 55, then'through bifurcated pipe 32 and flexiblehose 56 as inthe previous case.

It may be seen again that simultaneously with striker 17.is moved valve spindle 5 which occupies the new position shown in Fig. '6 thus closing bore 49 and opening bore 64. In this position oil under pressure remains admitted to piston 12 through the still opened bores 57 and 58 to impose pressure on striker 1'7- and-is adrnitted also to'piston ll through the-nowopened bores 64:and

65. In this sequence piston 11 moves in the direction 'shown 'by'arrow'66 until -striker-18 imposes 'a blow-on bracket 37 via members 39a and 39. Simultaneously, worked out oil discharged by pushed-in piston 10 escapes through bores 50 and 67 into bore 68, bifurcated pipe 32 and hose 56.

The moving striker 18 movesalso valve spindle 4 into the position shown in Fig. 7 thus C1OSiIlg1fbOI-6'57 and opening bore 47. In this final new position the oil under pressure whilst still admitted to piston 11 through the still opened bores '64 and 65 and thus still imposing a pressure onstriker "18, becomes admitted also tojpiston 13 through the now opened bores 47 and "48 thus forcing piston 13 and striker 17 to move :in the direction of .the arrow 69 (Fig. 7) until it imposes a blow upon bracket 38 via members 40a and 40. At'the'sa'me time worked out oil is discharged under the action of piston 12 and flows through bores 58 and 70 into bore 68, bifurcated pipe 32 and hose '56 as in the previous case.

It may be seenthat after completing the last described stroke the striker 17 comes to exactly the same position as shown in Fig.4 and already described. Thus it may be stated that the vibrator'works in cycles of four strokes orblows in each cycle. The cycles and blows continue uninterrupted as long as oil under pressure is supplied.

'The frequency of vibrations of a working structure caused by the vibrator in general is equal to the frequency of blows or strokes, the number per minute of which is four times greater'than the number of full cycles ofthe vibrator. Frequency or number of blows per minute of a given vibrator having a given diameter of pistons and length of strokes depends upon quantity of oil forced to flow through the vibrator. The quantity or volume of oil which can be forced through the vibrator depends on pressure. Thus the frequency of vibrations may be very easilyregulated by changing the pressure of oil supplied to the vibrator.

-A vibrator as described may be applied to any type of mining, conveying or other machine which employs a vibration 'efiect, examples of machines to which it can be applied being cutters, feeders, vibrator conveyors, screens and the like.

Obviously those skilled in the art may make various changes in the'details and arrangement of parts without departing'from the spirit and scope of the invention as defined by the claims hereto appended, and applicants therefore wish not to be restricted to the precise construction herein disclosed.

Having thus described and shown an embodiment of the invention, what it is desired to secure by Letters Patent of the United States is:

1. A vibrator including a combined valve and cylinder block, a pair of elongated strikers slidably mounted on saidblock for reciprocable motion in side by side parallel positions, each striker including a pair of striker heads, one at each end of a striker, a pair of hydraulic pistons'in 'saidlblock'for each of said strikers and positioned between said striker heads to provide for impartingreciprocable motion to each of said strikers, a hydraulic fluid feed supplyand discharge means connected to passages in the block communicating with said-pistons for supplying hydraulic fluid under pressure to operate said pistons, valve .'means including a spindle for each striker slidably mounted in said block for controlling the flow'of hydraulic fluid to and from said pistons, each spindlewmoving in one direction to admit hydraulic fluid under pressure to operate a piston and which moves in the opposite direction to discharge said fluid from the piston so operated, said strikers having end members which abut theends of said spindles whereby movement of the-strikers is transmittedto move the spindles first inonedirection and then in the opposite direction to provide for controlling the flow of hydraulic fluid to and from said pistons so "that hydraulic fluid "is admitted to drive each striker with a reciprocating motion and in a four-stroke cycle with respect to the striker heads.

2. A vibrator including a combined valve and cylinder block, a pair of elongated strikers slidably mounted on said block for reciprocable motion in side by side parallel positions, each striker including a pair of striker heads, one at each end of a striker, a pair of hydraulic pistons in said block for each of said strikers and positioned between said striker heads to provide for imparting reciprocable motion to each of said strikers, a hydraulic fluid feed supply and discharge means connected to passages in the block communicating with said pistons for supplying hydraulic fluid under pressure to operate said pistons, valve means including a spindle for each striker slidably mounted in said block for controlling the flow of hydraulic fluid to and from said pistons, each spindle moving in the direction to admit hydraulic fluid under pressure to operate a piston and which moves in the opposite direction to discharge said fluid from the piston so operated, said striker heads having integral 20 brackets at each end thereof which abut the ends of said spindles whereby the movement of the strikers is transmitted to move the spindles first in one direction and then in the opposite direction to provide for controlling the flow of hydraulic fluid to and from said pistons so that hydraulic fluid is admitted to drive each striker with a reciprocating motion and in a four-stroke cycle with respect to the striker heads.

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